2005-06-05 Peter Bartok <pbartok@novell.com>

[mono.git] / mcs / class / corlib / System.Security.Cryptography / CryptoStream.cs

diff --git a/mcs/class/corlib/System.Security.Cryptography/CryptoStream.cs b/mcs/class/corlib/System.Security.Cryptography/CryptoStream.cs
old mode 100755 (executable)
new mode 100644 (file)
index 2a19140..986279d
--- a/mcs/class/corlib/System.Security.Cryptography/CryptoStream.cs
+++ b/mcs/class/corlib/System.Security.Cryptography/CryptoStream.cs
@@ -9,6 +9,29 @@
 // (C) 2004 Novell (http://www.novell.com)
 //
 
+//
+// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
+//
+// Permission is hereby granted, free of charge, to any person obtaining
+// a copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to
+// permit persons to whom the Software is furnished to do so, subject to
+// the following conditions:
+// 
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//
+
 using System;
 using System.Globalization;
 using System.IO;
@@ -20,7 +43,6 @@ namespace System.Security.Cryptography {
                private Stream _stream;
                private ICryptoTransform _transform;
                private CryptoStreamMode _mode;
-               private byte[] _previousBlock;
                private byte[] _currentBlock;
                private bool _disposed;
                private bool _flushedFinalBlock;
@@ -119,11 +141,12 @@ namespace System.Security.Cryptography {
                        }
                        // yes - buffer.Length will throw a NullReferenceException if buffer is null
                        // but by doing so we match MS implementation
-                       if (offset + count > buffer.Length) {
+                       // re-ordered to avoid integer overflow
+                       if (offset > buffer.Length - count) {
                                throw new ArgumentException ("(offset+count)", 
                                        Locale.GetText ("buffer overflow"));
                        }
-                       // for some strange reason Object_disposedException isn't throw
+                       // for some strange reason ObjectDisposedException isn't throw
                        // instead we get a ArgumentNullException (probably from an internal method)
                        if (_workingBlock == null) {
                                throw new ArgumentNullException (
@@ -176,7 +199,7 @@ namespace System.Security.Cryptography {
                                                }
                                                byte[] input = _transform.TransformFinalBlock (_waitingBlock, 0, _waitingCount);
                                                transformed = input.Length;
-                                               Array.Copy (input, 0, _transformedBlock, _transformedCount, input.Length);
+                                               Buffer.BlockCopy (input, 0, _transformedBlock, _transformedCount, input.Length);
                                                // zeroize this last block
                                                Array.Clear (input, 0, input.Length);
                                        }
@@ -225,7 +248,8 @@ namespace System.Security.Cryptography {
                                throw new ArgumentOutOfRangeException ("count", 
                                        Locale.GetText ("negative"));
                        }
-                       if (offset + count > buffer.Length) {
+                       // re-ordered to avoid integer overflow
+                       if (offset > buffer.Length - count) {
                                throw new ArgumentException ("(offset+count)", 
                                        Locale.GetText ("buffer overflow"));
                        }
@@ -254,8 +278,6 @@ namespace System.Security.Cryptography {
                                        // transform all except the last block (which may be the last block
                                        // of the stream and require TransformFinalBlock)
                                        int numBlock = ((_partialCount + count) / _transform.InputBlockSize);
-                                       if (((_partialCount + count) % _transform.InputBlockSize) == 0) // partial block ?
-                                               numBlock--; // no then reduce
                                        int multiSize = (numBlock * _transform.InputBlockSize);
                                        if (numBlock > 0) {
                                                byte[] multiBlocks = new byte [multiSize];
@@ -263,17 +285,17 @@ namespace System.Security.Cryptography {
                                                _stream.Write (multiBlocks, 0, len); 
                                                // copy last block into _currentBlock
                                                _partialCount = count - multiSize;
-                                               Array.Copy (buffer, offset + multiSize, _workingBlock, 0, _partialCount);
+                                               Buffer.BlockCopy (buffer, offset + multiSize, _workingBlock, 0, _partialCount);
                                        }
                                        else {
-                                               Array.Copy (buffer, offset, _workingBlock, _partialCount, count);
+                                               Buffer.BlockCopy (buffer, offset, _workingBlock, _partialCount, count);
                                                _partialCount += count;
                                        }
                                        count = 0; // the last block, if any, is in _workingBlock
                                }
                                else {
                                        int len = Math.Min (_transform.InputBlockSize - _partialCount, count);
-                                       Array.Copy (buffer, bufferPos, _workingBlock, _partialCount, len);
+                                       Buffer.BlockCopy (buffer, bufferPos, _workingBlock, _partialCount, len);
                                        bufferPos += len;
                                        _partialCount += len;
                                        count -= len;
@@ -334,13 +356,10 @@ namespace System.Security.Cryptography {
                                        Array.Clear (_workingBlock, 0, _workingBlock.Length);
                                if (_currentBlock != null)
                                        Array.Clear (_currentBlock, 0, _currentBlock.Length);
-                               if (_previousBlock != null)
-                                       Array.Clear (_previousBlock, 0, _previousBlock.Length);
                                if (disposing) {
                                        _stream = null;
                                        _workingBlock = null;
                                        _currentBlock = null;
-                                       _previousBlock = null;
                                }
                        }
                }